You canot export files to FLV and F4V formats in the June 2014 and later versions of After Effects CC. Use After Effect CC (June 2013) or below to export files to FLV and F4V formats.

You can render and export movies from After Effects as
movies that can play in Adobe Flash Player. SWF files play natively
in Flash Player, whereas an FLV or F4V file must be contained in
(or linked to from) a SWF file to play in Flash Player. You can
also export compositions to Flash Professional as XFL files.

This video from the After Effects CS5: Learn By Video series
provides an overview of exporting to the various formats for Flash
Professional and Flash Player, and demonstrates the use and common
issues with each.

XFL

XFL files are representations of compositions
that can be opened in Flash CS4 Professional or later. XFL files
are essentially the XML equivalent of FLA files.

SWF

SWF files are small files that play
in Flash Player. They are often used to deliver animated vector
graphics (such as cartoons), audio, and other data types over the Internet.
SWF files also allow viewer interaction, such as clicking to follow
a web link, control animation, or provide input to a rich internet
application (RIA). SWF files are the output created from FLA files.

FLV and F4V

FLV and F4V files contain
only pixel-based (rasterized) video, not vector graphics, and they
aren’t interactive. FLA files can contain and refer to FLV and F4V
files, which are then embedded or linked in SWF files that play
in Flash Player.

Export a composition as an XFL
file to Flash Professional

You can export a composition from After Effects to the XFL format for further modification and use in Flash CS4 Professional or later. For example, you can use ActionScript in Flash Professional to add interactive animation to each of the layers from an After Effects composition.

When you export a composition as an XFL file, After Effects attempts to export individual layers and keyframes, preserving as much information for direct use in Flash Professional as it can. If After Effects can’t export an element of a composition as unrendered data in an XFL file, the element is either ignored or rendered into a PNG or FLV item, depending on whether you choose to ignore unsupported features.

About XFL files

XFL files are essentially the XML equivalent of FLA files.
An XFL file is a compressed archive folder that contains a Library
folder and an XML document (DOMDocument.xml) that describes the
FLA file. The Library folder contains the assets referred to by
the XML file. When you open an XFL file in Flash Professional, it
extracts these items from the XFL file and uses them to build a
FLA document. You save the document from Flash Professional as a
new FLA file; you do not change the XFL file with Flash Professional.

If you want to examine or manually edit the contents
of an XFL file, you can open the compressed archive file in the
same manner as any other .zip file. Changing the filename extension
to .zip is not necessary, but it may make extracting the files for
this manual examination more convenient.

This video from the After Effects CS5: Learn By Video series
demonstrates export to XFL.

Exporting a composition to XFL
format

In the Adobe Flash Professional (XFL) Settings dialog box,
choose what After Effects will do with layers with unsupported features:

Ignore

Layers with unsupported features are not included in the
XFL output.

Rasterize To

Layers with unsupported features are rasterized. This means that
the layers are rendered to a bitmap format (an FLV file or a sequence
of PNG images). Vectors are not preserved. This preserves the appearance
of the layer when the XFL file is used in Flash Professional. When
rasterizing to a PNG sequence, identical adjacent frames are rasterized
only once, to a single PNG file that is referenced multiple times.

(Optional) Click the Format Options button and modify the
settings used for creating PNG sequences or FLV files.

If
you click Format Options when FLV is chosen in the Format menu,
the export settings dialog box opens. Though you can modify such
items as the bit rate, in general you won’t need to change many
settings in this dialog box. Changes that you make in this dialog
box persist and are used for subsequent export operations, so be
careful about what you change.

If you make a change to the
format options that you would like to undo, click the Reset To Defaults
button in the Adobe Flash Professional (XFL) Settings dialog box.

In the Export As Adobe Flash Professional (XFL) dialog box,
choose a location for the output files.

As the composition is being processed, a dialog box shows the
progress of the export operation.

When After Effects creates an XFL file, it also saves a report
([XFLfile_name] report.html) to the same folder
as the XFL file. The report indicates the following:

whether layers with unsupported features were rasterized
or ignored

whether each source item was rasterized (“rendered”) or passed
through (“linked”)

whether each layer was rasterized (“rendered”) or converted
to a native Flash object

Working in Flash Professional with
a FLA document created from an XFL file

The Library panel in Flash Professional is similar to the
Project panel in After Effects. When Flash Professional creates
a FLA document from an XFL file, it creates symbols, folders, and
video clips and organizes them in the Library panel. Each item in
the Library panel has a unique name—even if they are based on items
with identical names in After Effects—so that these items can be
manipulated using ActionScript. This requirement for unique naming
causes After Effects to append underscore characters and numerals
to many names when creating the XFL file.

When Flash Professional builds a FLA document from an XFL file
that includes FLV files, the FLV files are embedded in the timeline
in Flash. Often, a more efficient way to construct a FLA document
is to move the video files to an external location referenced by
the SWF file to stream the video. You can unembed FLV files as appropriate
within Flash Professional, by deleting the video and importing it
again using the FLVPlayback component.

Note:

In After Effects, the composition’s timeline begins at frame
0. In Flash Professional, the timeline begins at frame 1. This difference
causes the After Effects composition timeline and the corresponding
Flash timeline to appear to be offset from one another by one frame.

In After Effects, a composition can have pixel aspect ratios
other than 1.0 (square pixels). Flash Professional only supports
a pixel aspect ratio of 1.0. When a composition is exported to XFL
format, the FLA document is a square-pixel document with a different
number of pixels so that the appearance of the document in Flash
Professional matches the appearance of the composition in After
Effects. Scale values in the XFL file preserve the appearance of
the layers.

How features and data are preserved
when exporting a composition to XFL format

When a composition is exported as an XFL file, After Effects goes through multiple stages, attempting at each stage to export the maximum amount of information from layers and their source files.

If the composition uses PNG, JPEG, and FLV files as the sources for its layers, these source files are included in the XFL output (passed through) unless the layers use features that force After Effects to transcode the source files or rasterize the layers for export to XFL.

Note:

Transcoding is the conversion of a source file from one format to another format, such as from GIF to PNG. Rasterizing is the conversion of a layer to a bitmap image, incorporating all of the model information—such as vectors and keyframes—into a flattened, pixel-based image for each frame.

Stage 1: Source files are passed through unchanged,
if possible.

For a layer’s source file to be passed through
to the XFL file, the layer must meet these requirements:

The layer has a source footage item, and that footage item
uses a PNG or JPEG sequence or FLV file as its source. (The layer
is not a text layer, camera layer, light layer, or shape layer.)

The layer does not extend before the first frame or after
the last frame of the composition work area.

The layer has no properties other than Position, Anchor Point,
Opacity, Scale, and Rotation. Because effects add properties to
layers, this requirement also means that the layer has no effects
applied.

The layer does not have motion blur, frame blending, or time-remapping applied.

The layer does not have a track matte.

There is no adjustment layer above the layer.

Layers above do not use blending modes other than Normal.

The layer does not have the Preserve Transparency option
set, nor does any layer above it.

If the only reason
that a layer’s source file can’t be passed through to the XFL file is
that it doesn’t use a PNG sequence, JPEG sequence, or FLV file as
its source, then the layer’s source is transcoded or rasterized
to a PNG sequence or FLV file, which is included in the XFL file.
In this case, the layer’s Position, Opacity, Scale, and Rotation
keyframes are preserved and converted to keyframes in the XFL output. If
multiple layers use the same source in After Effects and meet all
of the other pass-through requirements listed above, they will also
share a common source in the document created in Flash Professional.
Precompositions can be rasterized as source items.

The XFL
file created from a composition preserves the animation information
for the layers in the composition. Keyframes for the Position, Opacity,
Scale, and Rotation properties are converted to keyframes in Flash
Professional, with one keyframe per frame for each animated property.
Only 2D Position (x and y) keyframes and 2D (z) Rotation keyframes
are converted.

In After Effects, the Anchor Point property
can be animated, but the transformation point in Flash Professional
can’t be animated. In Flash Professional, the transformation point
is located at the top-left corner of the symbol. Keyframe animations
of transform properties (including Anchor Point) in After Effects
are converted to animations based around the transformation center
in the exported XFL file.

If a layer doesn’t meet the requirements
for its source file to be passed through, transcoded, or rasterized
as a source item, then the layer itself must be rasterized as a
layer. Rasterizing a layer means that all of its keyframe information
is lost—all of the information is contained in the rasterized image
frames themselves.

To be rasterized as an individual layer,
a layer must meet these requirements:

The layer is
either based on a video footage item (including a solid) or is a shape
layer or text layer. (The layer is not a camera layer, light layer,
or audio-only layer.)

There is no adjustment layer above the layer.

Layers above do not use blending modes other than Normal.

The layer does not have a track matte.

The layer does not have the Preserve Transparency option
set, nor does any layer above it.

The layer is not a 3D layer.

Stage 4: Remaining layers are rendered and rasterized
together in bins.

If a layer doesn’t meet the requirements
for rasterization to an individual layer, then it is rendered and
rasterized together with other layers in a group (bin).
Bins of layers that are rasterized together are generally 3D layers,
layers that are composited together with blending modes, track mattes,
and layers affected by an adjustment layer.

Limitations of exporting a composition
to XFL format

When Flash Professional opens an XFL file, it must load
all of the assets into memory. After Effects warns you when you
export a composition for which the assets will consume more than
580 MB. Similarly, After Effects warns you if the amount of time
that an XFL file will take to open in Flash Professional is very
large because the number of frames in a PNG sequence is greater
than 1,050. You can still export a composition to XFL format if
it exceeds these limits, but you may not be able to open the XFL
file with Flash Professional.

To prevent the long load times related to sequences
with a large number of PNG files, consider pre-rendering layers
based on PNG sequences to FLV format.

After Effects relies on the embedded version of the Adobe Media
Encoder to create FLV files. The Adobe Media Encoder can’t create
FLV files with pixel dimensions greater than 1920x1080.

When you export a composition to the XFL format from a 32-bpc
project, the rendering of colors with values under 0 and over 1
does not produce results that preserve the appearance of the composition
in After Effects. You should only work in an 8-bpc or 16-bpc project
when creating a composition that you intend to export to Flash Professional
in XFL format.

Render and export a composition
as a SWF file

SWF files are small files that play in Flash
Player. They are often used to deliver animated vector graphics
(such as cartoons), audio, and other data types over the Internet.
SWF files also allow viewer interaction, such as clicking to follow
a web link, control animation, or provide input to a rich internet
application (RIA). SWF files are the output created from FLA files.

While
rendering and exporting a movie to a SWF file, After Effects maintains vector
graphics as vector objects as much as possible. However, raster
images, blending modes, motion blur, some effects, and the contents
of nested compositions cannot be represented as vectors in the SWF
file and are rasterized.

You can choose to ignore these unsupported
items so that the SWF file includes only the After Effects features
that can be converted into native SWF elements, or you can choose
to rasterize frames that contain unsupported features and add them
to the SWF file as JPEG-compressed bitmap images, which may reduce
the efficiency of the SWF file.

Audio is encoded in MP3 format
and added to the SWF file as an audio stream.

When After Effects
creates a SWF file, it also saves a report ([SWFfile_name]R.htm) to
the same folder as the SWF file. The report also contains a link
to the SWF file so that you can preview the output using the Flash
Player plug-in. Open the report in a browser to view the SWF file
and see which items in the composition are unsupported.

The
exported SWF file includes each unchanged item in the After Effects
composition once, and then references it for each use. If a layer
is used in multiple frames, each use refers to the same object,
even if the layer’s transform properties (such as Position) are
animated. However, if the content of the layer changes—for example,
if a mask on the layer is animated or if the source footage item
for the layer is video—a new object is created for each frame in
which the layer is visible. If multiple layers in the composition
share the same source footage item, the source is added once and
is then referenced for every additional layer that shares the source.
If the source is an Illustrator file, a SWF movie clip is created
and referenced. Text characters are added as vectors once and then
referenced on all subsequent frames, unless you choose Fill Over
Stroke from the Fill And Stroke options menu; in that case, the
characters are added as vectors on every frame.

Note:

If color
management is enabled for the project, then colors are converted
from the working color space of the project to the sRGB IEC61966-2.1
color space for output. This output color space is appropriate for
movies shown in a web browser. (See Color
management.)

Select the composition you want to export, and
then choose File > Export > Adobe Flash Player (SWF).

Enter a filename (making sure to include the .swf extension)
and location, and then click Save.

Specify options as appropriate, and then click OK.

Chris Jackson provides tips for rendering and exporting
SWF files from After Effects in an excerpt from his book Flash + After Effects on
the Focal Press website.

SWF export settings

JPEG Quality

Specifies the quality of rasterized images. The higher the
quality, the larger the file. (If you select Rasterize for Unsupported
Features, the JPEG Quality setting is used for all JPEG-compressed
bitmap images exported to the SWF file, including bitmap images
generated from composition frames or Adobe Illustrator files.)

Unsupported Features

Specifies whether to rasterize features that SWF format doesn’t
support. Choose Ignore to exclude unsupported features, or choose Rasterize
to render all frames that contain unsupported features as JPEG-compressed
bitmap images and include them in the SWF file. If you choose Rasterize,
the SWF exporter rasterizes source files for each layer in the composition
(except layers that use Illustrator files or solids as the source
footage) and nested compositions with Collapse Transformations enabled.

Audio Bit Rate

The bit rate of the exported audio. Choose Auto to get the lowest
bit rate available for the specified Sample Rate and Channels settings. Higher
bit rates increase file size. Audio in a SWF file is in MP3 format.

Loop Continuously

Specifies that the exported SWF file loops continuously during
playback. If you plan to specify looping by writing HTML code to
control Flash Player, deselect Loop Continuously.

Prevent Editing

Creates a SWF file that can’t be modified by applications
such as Flash Professional.

Include Object Names

Includes layer, mask, and effect names in the file, for use as
input to ActionScript programs. Selecting this option increases
file size. Rasterized objects are not named.

Each mask is
exported as a separate SWF object, the name of which is the layer name
followed by the mask name. If all masks use Difference mode, all
masks are exported as one SWF object, and the name is the layer
name. Each text character is exported as a separate SWF object.

Flatten Illustrator Artwork

Splits all overlapping objects into non-overlapping pieces.
When you select this option, you don’t need to convert Illustrator
text to outlines before exporting. (This option supports source
files from Illustrator 9.0 or later.)

Flattening Illustrator
artwork has advantages and disadvantages. When you flatten Illustrator
artwork, text is exported to SWF format properly, so you don’t need
to convert text to outlines. Overlapping objects are removed, so composited
layers appear the same in both After Effects and the SWF file. End caps,
joins, and transparency groups are exported properly, and artwork
outside crop marks, which is not visible in the SWF file, is not
included. However, SWF files don’t necessarily become smaller. In
addition, the flattening process may introduce unsupported objects
that are then ignored or rasterized, and white fringes may appear
around some objects. The process can be slow, memory-intensive,
and possibly ineffective for complex Illustrator artwork.

Include Layer Marker Web Links

Makes layer markers behave as web links. The Include Layer
Marker Web Links option adds web links and a Get URL action to the
SWF file by using information from layer markers. This option also
adds a frame label to each SWF frame that has a layer marker. You
can specify how the browser opens the web link with standard target
commands (for example, _blank). (See Web
links, chapter links, cue points, and markers.)

Target commands for web links in
a SWF file

_blank

Loads the web link into a new browser window.

_parent

Loads the web link into the parent frame of the frame in
which the current file is playing.

_self

Loads the web link into the current frame.

_top

Loads the web link into the top frame in the current window.

_level0

Loads another SWF file into level 0. The current file typically
plays at level 0; another file loaded into level 0 usually replaces
the current file. The URL must refer to another SWF file.

_level1

Loads another SWF file into level 1 if the URL refers to
another SWF file.

Only masks with Add mask mode or Difference mask mode are supported;
multiple masks in a layer must use the same mask mode. If Add mode is
specified, partial opacity and the Inverted option are also supported.
Mask feather is not supported. The result of overlapping masks with
Add mode and partial opacity may appear differently in the SWF file
than in After Effects. (See Mask
modes.)

All Path Text options are supported,
except the following: Composite On Original, Fill Over Stroke, and
Difference mode.

Lines drawn by the Audio Spectrum and Audio
Waveform effects are converted to vectors. The following unsupported
features are ignored: Outside Color (only Inside Color is used),
Softness, and Composite On Original. In addition, only uniformly
thick lines are included in the SWF file. For example, if you select
the Use Polar Path option in Audio Spectrum, lines become thicker
farther from the center in After Effects, but in the SWF file the
lines remain at the same thickness.

The waveforms may increase
the SWF file size, so decrease the Displayed Samples value in the
Audio Waveform effect or the Frequency Bands value in the Audio Spectrum
effect, or decrease the frame rate to make the SWF file smaller.

Resolution

SWF files are always created at full resolution (size of
composition); JPEG-compressed bitmap images are rendered at full
resolution.

Adobe Illustrator files

Only stroked paths and filled paths in CMYK or RGB color spaces
are supported.

Layers that have Illustrator source files
are converted to corresponding SWF items if the layer does not contain
masks or have Collapse Transformations enabled. Illustrator layers
that contain masks or have Collapse Transformations enabled are
rasterized. The SWF file maintains the Illustrator crop marks. Artwork outside
the crop marks is included in the SWF file even though it’s not
visible, thereby increasing the file size.

The SWF export
report lists information for unsupported features in Illustrator files
for the first frame in which the Illustrator file is visible. Unsupported
features are ignored or rasterized (depending on whether you’ve
selected Ignore or Rasterize Unsupported Features) on all frames
in which the footage is visible.

Render and export a composition
as an FLV or F4V file

FLV and F4V files contain only pixel-based (rasterized) video, not vector graphics, and they aren’t interactive.

The FLV and F4V formats are container formats, each of which is associated with a set of video and audio formats. FLV files generally contain video data that is encoded using the On2 VP6 video codec and audio data encoded using an MP3 audio codec. F4V files generally contain video data that is encoded using an H.264 video codec and the AAC audio codec.

Note:

After Effects CS4 and earlier also provided the option to encode video data in FLV files using the Sorenson Spark video codec.

You can play a movie in an FLV or F4V container file in many different ways, including the following:

Import the file into the Flash Professional authoring
application and publish the video in a SWF file.

Play the movie in the Adobe Media Player (AMP).

Preview the movie using Adobe Bridge.

After Effects markers can be included as cue
points in an output FLV or F4V file. To transfer keyframes or global
property values into the Flash Professional authoring application
from After Effects, run the Convert Selected Properties To Markers.jsx script
before rendering and exporting an FLV or F4V file.

To include the alpha channel in the FLV output, use the On2 VP6
codec and select Encode Alpha Channel in the Video tab of the export
settings dialog box. After Effects premultiplies channels with black
when encoding transparency in FLV files. (See Alpha
channel interpretation: premultiplied or straight.)

When you render and export a composition to the F4V or FLV format
from a 32-bpc project, the rendering of colors with values under
0 and over 1 does not produce results that preserve the appearance
of the composition in After Effects. To avoid unexpected results,
you can work in an 8-bpc or 16-bpc project when creating a composition
that you intend to render and export to F4V or FLV format. Alternatively,
you can work in a 32-bpc project, render and export the composition
to another format, and then convert the output file to F4V or FLV.

Online resources about FLV and
F4V formats

This video from the After Effects CS5: Learn By Video series
demonstrates export to FLV and F4V formats.

Robert
Reinhardt provides information about video for Flash Player in some sample
chapters from his book Video with Adobe Flash CS4 Professional Studio Techniques on
the Peachpit website. In the "Compression primer" chapter, he explains
in detail the advantages and disadvantages of the On2 VP6 and H.264 video
codecs.